1. Field of the Invention
The present invention relates to glucans obtained by treating microorganism cells belonging to the genus Aspergillus by specified methods and to methods for using them.
2. Brief Description of the Background Art
Fungal (1→3)-β-D-glucans show various biological activities such as activation of reticuloendothelial system including production of various cytokines from macrophage, activation of complement system, antitumor activities (e.g., lentinan prepared from Lentinus edodes, schizophyllan prepared from Schizophyllum commune and the like are now on the market as medicaments having antitumor activities) and the like (Yakugaku Zasshi, 120(5), 413–431 (2000)).
Deep-seated mycosis is one of the serious infectious diseases in the field of medical treatment. Since fungal (1→3)-β-D-glucan is eluted in blood when the infection with a fungus occurs, the deep-seated mycosis can be detected by measuring (1→3)-β-D-glucan in blood.
In addition, there are reports that not only (1→3)-β-D-glucan is regarded as one of the causative agents of allergic respiratory disorder, but also (1→3)-β-D-glucan of a microorganism entered into the living body increases the activity of endotoxin, so that its interfusion into blood as a foreign matter is extremely undesirable. Thus, contamination of medicaments, medical tools and the like with (1→3)-β-D-glucan is also becoming a serious problem from the viewpoint of medical treatment, so that detection of (1→3)-β-D-glucan is seriously required in the field of medical treatment.
Also, the sensitivity and accuracy of the detection of (1→3)-β-D-glucan are influenced by the sensitivity and accuracy of the reaction of a standard substance with a (1→3)-β-D-glucan detection reagent (e.g., limulus reagent, reagent containing a factor in phenoloxidase precursor cascade or the like). WO 99/11671 describes a method for extracting (1→3)-β-D-glucan having accurate reactivity with a (1→3)-β-D-glucan detection reagent from a microorganism belonging to the genus Candida, and the (1→3)-β-D-glucan obtained thereby. However, its sensitivity and the like were not sufficient.